Correction: There doesn't seem to be an argument when it comes to accepting "helper tweeters" in this forum so why not add coaxials to the list. As mentioned earlier, most of the sound the coaxial produces would be cabinet dependant as opposed to cross-over dependant (as full rangers are), so I don't think they qualify as multi-driver anyhow. Make that multi-drive units.
If you add a helper tweeter to a full-range driver and the full-range driver runs full-range, then it is a full-range system. The same system with a crossover on the full-range driver (e.g. Jim Griffin's JX92S/G2si design), makes it a two-way system, no longer full-range. Coax speakers require an electrical crossover on the lower and upper frequency units, therefore belong in the multi-way camp, as I see it.
I have two pairs of vintage Coral (Japan) coaxial speakers that use a single 2 uF cap to block LF's from the tweeter.
The main (8") driver runs full range.
Coral also made bullet tweeter versions, mine have an open cone tweeter, that used an L-Pad and a cap on the tweeter (again the LF driver runs full range).
The main (8") driver runs full range.
Coral also made bullet tweeter versions, mine have an open cone tweeter, that used an L-Pad and a cap on the tweeter (again the LF driver runs full range).
The current coaxials I own have a 12" bass and a 4" cone tweeter. There is a small cap to filter the lows to the tweeter. Quite similar to other fullrangers with a "helper tweeter" I've seen here. The bass driver appears to be "running its full range" in absence of any filtering components. There was nothing resembling a crossover in either the cabinets or attached to the driver unit itself. As I mentioned earlier- early 70's possibly 60's vintage.
The tweeter sounds the same whether in or out of a cabinet. The bass and mid's performance, much like a full ranger, is effected by cabinet size, type, etc.
Sounds more like a full range candidate to me. Or am I wrong?
The tweeter sounds the same whether in or out of a cabinet. The bass and mid's performance, much like a full ranger, is effected by cabinet size, type, etc.
Sounds more like a full range candidate to me. Or am I wrong?
with all due respect to members of the profession, it's high-end recording studios that are responsible for a lot of what passes for music these days - and damaged hearing on the part of the mixing engineers or session producers is not necessarily the reason why much of it is dreck
another resource of highly experienced "listening professionals" that you wouldn't want to tap for advice or opinions regarding your DIY projects would be purveyors of the few remaining high end audio salons,
for fun you could always ask a member of the Geek Squad at your local big box store whether (s)he prefers pentode / UL output configuration on a vacuum tube power amp
Let's not lump them all together now. There are good engineers and bad, of course. There are studios that make bad music, and studios that make good music. In large part, the difference is in the clients that they cater to. If a client wants dreck, that's what they'll get, and plenty of them do, I was surprised how often clients will reject a really good mix because it's not compressed enough, or not distorted enough, etc, etc. Sometimes it really frustrates the engineers. Sometimes they don't even want the credits on the label.
If an artist is not good, the recording will not be good, although it is amazing what can be done if the engineer is creative. If the engineer is just mastering a poor recording, there is only so much to be done with that.
Many, if not most times, there is a different studio involved in each step of the production. One studio does the recording, another masters, etc. Studios do not have as much creative control as they would like.
Hi Guys,
Its worth considering some driver history. Once the transistor came about and lots more power was on tap, the market for hi-efficency single cone drivers reduced. Along with the technical challenges of making a single large cone emit to 20kHz, its no small wonder that coaxial became more fashionable, mainly driven by commercial factors.
However, there's no escaping the mechanical and phase compromises that coaxial, whizzers and plugs produce. A single emitting surface with a graduated profile offers less emittance compromises. But we're back to the other problem, one of power-handling. Alas, a pure full-range single cone driver (mid to high efficiency) is less able to be driven at higher loads.
As we all often say: "no free lunch" in audio speaker design.
Cheers
Mark.
Its worth considering some driver history. Once the transistor came about and lots more power was on tap, the market for hi-efficency single cone drivers reduced. Along with the technical challenges of making a single large cone emit to 20kHz, its no small wonder that coaxial became more fashionable, mainly driven by commercial factors.
However, there's no escaping the mechanical and phase compromises that coaxial, whizzers and plugs produce. A single emitting surface with a graduated profile offers less emittance compromises. But we're back to the other problem, one of power-handling. Alas, a pure full-range single cone driver (mid to high efficiency) is less able to be driven at higher loads.
As we all often say: "no free lunch" in audio speaker design.
Cheers
Mark.
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To all of you who suggested MJK's design, thank you. It sounds exactly right for me and I'm following up on it. The only thing I may want to do is use a less expensive full ranger. The Jordan is just a tad too much for me, but in his articles, he talks about others such as some Fostex's and others with similar characteristics. I have heard that he is pretty responsive to questions and I do have a few. I'll ask a couple of them here.
1. I'd like specific suggestions for alternate full rangers that would work in this combination. Or, is the extra cost easily justified? I understand that I would need to get a speaker with similar Qts and sensitivity, etc to work well with this woofer. My hearing ends at about 10 or 11Khz, so really wide highs is not important, although I want it to be good for others too. Some of them, like the Alpair's go to 30 which is totally unnecessary for me. Maybe something that produced smooth, quality mids and low treble would be the best compromise since I rely the most on that range.
2. I understand that passive crossovers are considered an evil, if a necessary one. MJK's system had two iterations; the first one used active crossover with two separate amps, and for the second, he developed a passive network for those who didn't want to mess with active, but that was the only difference. I just read a very interesting article on active vs passive crossovers. Active Vs. Passive CrossoversThe author is clearly anti-passive,but presents a compelling argument for active. My question is, in this case of a woofer-augmented full-ranger, how about some kind of modified active crossover to reduce expense. For example, letting the midrange do its own thing without filter and maybe providing the woofer with a low pass. Or even no crossover at all but maybe use EQ for one or the other? One of the things I like about active is that you have so much control over it. My goal is not necessarily a calculated, MathCad-produced "true to the source" reference, but rather what sounds good to me and I like a lot of control. Just thinking out loud here and I welcome any comments and suggestions.
OK, if it has more than one voice coil it is eliminated from the full range realm. How's that?
Which makes me ask: Is the intent of this sub-forum to address systems or the drivers themselves? Judging from the posts, it sounds like the use of crossovers is the biggest issue and discussions involving helpers is welcome. I just want to make sure my questions fall into the right forum... In any case, it's a very interesting forum and I learn a lot here.
In my case, I'm interested in woofer-augmented FR systems and I'm leaning heavily towards building MJK's system described here http://www.quarter-wave.com/Project08/Jordan.pdf. , using two-amp active system allowing a lot of control over frequency spread. Hopefully, this is a good topic for this forum because I like it here.
So Grasshopper, you choose to challenge the Master?
Let's just say that the Whizzer Cone acts like a mechanical crossover, although I would prefer using electrical transfer function over voice coil in any definition. A dual voice coil driver could still be used in a fullrange manner with the second VC having a resistive load across it to adjust the "Q" of the driver.
This application was something that I came up with many years ago, but it really caught on after I mentioned it on the old "Bass List" in conjunction with the design of the "Official Bass List Subwoofer" which Dan Wiggins was the primary designer. He (and several others) liked the idea so well that they did the applicable math and simulations and it was later included in Dan's white paper related to the design. For this application, Dan came up with the term "RDO."
This "Official Bass List Subwoofer" later went commercial as the Avatar Audio (later Adire) "Shiva" subwoofer driver. I believe that NHT's Tonegen 1259 driver (Ken Kantor) and the "Shiva" driver were primarily responsible for the affordable subwoofer boom that followed.
Best Regards,
TerryO
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Goodmans Axiom 80 would be a good example of a driver designed by the father of full rangers wherein controlled decoupling of the main cone as well as use of a separate rigid "whizzer" achieved a virtual multi-way system driven by a single motor assembly
this 40+yr old driver is clever in so many ways,
Goodmans Axiom 80
but I digress - for my money, it's the attempt to get widest bandwidth using a single motor assembly (regardless of number of voice coils or method used to develop the permanent magnetic flux ) per (compound) emitting surface(s) that defines a "full range" driver - clearly not as easy a goal to achieve as to define
this 40+yr old driver is clever in so many ways,
Goodmans Axiom 80
but I digress - for my money, it's the attempt to get widest bandwidth using a single motor assembly (regardless of number of voice coils or method used to develop the permanent magnetic flux ) per (compound) emitting surface(s) that defines a "full range" driver - clearly not as easy a goal to achieve as to define
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Actually, what exactly constitutes a 'full range' driver is a good question (for which the answer I think has already been provided here). But, wrt the HT speakers I am currently finishing up on, 8 of the 9 drivers are not operated quite full (range), being rolled off on the high end, but the center one is, although peaked in response by up to 10db at ~20Khz to balance the lower frequency energy of the other eight. I calculated that this peaking would not cause an excessive drop in impedance at the terminals, since the driver inductance drives the impedance to above 50 ohms at that frequency.
No reason why a "full range" cannot have a whizzer and or a phase plug.
However a whizzer and a phase plug are two different things.
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